1998 Ford Taurus SE
Vulcan 3.0L OHV V6 generating 145hp
VIN (U)

If it has "timing belt",when should i change it?

it has a chain

You can check the chain by putting a large socket on the lower crankshaft pulley bolt, remove the distributor cap and slowly turn the crank until you see the rotor move, stop, reverse the socket wrench and see how much the crank pulley must turn in the other direction before the rotor starts to turn. There should be very little play.

Thank you!